Phase shifting device for blade folding mechanism



April 6, 1965 E. GRAF ETAL 3,176,977

PHASE SHIFTING DEVICE FOR BLADE FOLDING MECHANISM Filed Nov. 19, 1962 Ami-nay:

$376,977 PHASE SHIFHNG DEVICE Ffilli FQLDING REQHANESM Erwin Graf and Karl R. Scheuter, Zurich, Switzerland, assignors to ltdascninenfahrih Wrinkles, Faliert Q0. ALL, Berne, witzerland Filed Nov. 19, E62, Ser. No. 238,425

Claims priority, application Sweden, Nov. 2%}, H61,

11,535/ 61 2 Claims. (Cl. 270-77) This invention relates in general to folding mechanism and particularly to a new and useful folding mechanism for articles such as printed forms and the like, which includes a folding knife for directing the elements or articles between cooperating rollers for folding the same and to means permitting the automatic shifting of the knife in accordance with the feeding of the articles thereto.

The present invention has particular application for the folding of prefolded printed forms. With a machine of this character, it is usual to convey the prefolded forms between conveyor tapes onto a folding table. A rotating folding knife is then operative to push the forms between two folding rolls in order to create a finished folding of the form and then convey it away. With a machine of this character, it is essential that the folding knife push the forms into the folding rolls at the right moment in order to precisely locate the fold line. For this reason, it must be possible to adjust the folding knife in order that its position can be adapted to the forms coming from the prefolding mechanism.

In machines of this character which have been known, a setting device is employed but such setting device permits adjustment of the folding knife only when the machine is turned off or inoperative. In practice, it has been found that it is very difficult to exactly adjust the folding knife to correspond to the particular speed of rotation or operation of the machine. Depending on the speed of the machine, the forms will reach the folding table either sooner or later in respect to the operation of the folding knife. At higher speeds, the forms move forward and reach the folding table too early compared with the operation of the folding knife, out if the machine runs more slowly then the forms lag behind the operation of the folding knife. The result is that the forms often get into the folding rolls too far either in back or in front of their desired location, depending on the speed of operation of the machine. While this variation of position of the folded form is not very great at small speeds, it has been found that it becomes excessive at high speeds and in some instances the folded forms bunch up alongside the folding rings or rolls and can no longer be correctly conveyed to the delivery conveyor.

In accordance with the invention, there is provided means for operating the folding knife so that it may be adjusted while it is running. In addition, means are provided for sensing the angular position of the folding knife and for scanning the speed of advance of the articles to be folded into association with the knife. The scanning means is arranged to operate in association with the means for sensing the angular position of the knife, and means are provided for adjusting the angular location of the knife in accordance with the feed of the articles to the knife, The machine operation is so that the knife is adjusted automatically in accordance with the feed of each of the articles to the knife for folding operation.

In accordance with one embodiment, the scanning means includes a pair of photoelectric cell components which are located in spaced relationship along the length of the knife and which operate in conjunction with an additional photoelectric cell arranged to sense the angular position of the folding knife to operate on the articles. The combined photoelectric cell means is operative $376,977. Patented Apr. 6, 1955 through a controller to shift the position, or to adjust the phase relation, of the folding knife in accordance with the position of the article which is sensed by the photoelectric cells.

Accordingly, it is an object of this invention to provide an improved device for folding articles such as printed forms.

A further object of the invention is to provide a device for folding articles which includes a rotatable knife for directing the articles between rolls for the purpose of folding the same, and further including means for sensing the timing of the feed of the articles to the knife and for adjusting the angular position of the knife in accordance therewith.

A further object of the invention is to provide a device for folding articles such as printed forms which are fed by conveyor means in succession to a rotatable knife, said knife being mounted so that it may be angularly displaced, and sensing means for sensing both the angular position of the knife and the delivery of articles to the knife for folding operations, including control elements for phase shifting the knife in accordance with the sensing means.

A further object of the invention is to provide a device for folding printed forms and the like which is simple in design, rugged in construction and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

In the drawings:

FIG. 1 is a somewhat schematic side elevational view, partly in section, of a folding machine constructed in accordance with the invention; and

FIG. 2 is a section taken on the line 2'2 of FIG. 1.

Referring to the drawings in particular, the invention embodied therein includes a rotatable knife assembly generally designated 1 which is mounted on a shaft '7 which is rotated from a power shaft 8 by means of helical gearing 2 and 3.

Shaft 7 has secured thereto diametrically extending and axially spaced arms a and b interconnected by a relatively heavy member 1. At points diametrically opposite the connecting member 1, the arms la and lb are provided with bearings 11]) and 11c for a shaft 11a carrying the folding knife 11. Shaft 11a has an axial extension 11d carrying a pinion Me which meshes with an internal ring gear lily. The cooperation of the gears lle and ll effects the rotation of knife blade 11 in the direction of the arrow 43 in FIG. 2, while the assembly 1 is rotating in the direction of the arrow 42.

in accordance with a feature of the invention, the helical gear 2 is made axially elongated to permit shifting .of the driving relationship of the gear 3 therewith and hence relative angular displacement of the shaft '7 and the knife assembly 1. Means are provided to control the shifting of the knife assembly 1 which includes a servo motor 4 which is arranged to rotate a control screw 5 for the purpose of advancing or retarding a yoke member or fork 6 which axially adjusts the gear 3 along the shaft 7. The shaft 7 is rotatably mounted on spaced bearings 39 and 32. Gear 3 is keyed to rotate with shaft 7, but is axially adjustable therealong.

Articles such as initially folded printed forms 10 are advanced over a work table 34 having an opening 36 defined therein above cooperating folding rollers 12 at a location midway therebetween. The articles are fed by veyor rollers 38 and 4%, respectively. Therollers 38 and 45B are driven at an adjustable constant so that the speed of advance of the articles 10 into association with the knife assemlby may be adjusted.

The knife assembly 1 includes an outwardly extending folding knife blade 11 which is rotated with the assembly in the direction of the arrow 42 (FIG. 2) and which also a is rotated in the direction of the arrow 43 during its operative cycle to effect the infolding of the articles 10 between.

the two rollers 12 and the dropping downwardly thereof as indicated in FIG. 2.

The invention provides means for sensing the arrival of each article 10 and for correcting the angular position of the knife blade 11 so that it will be operative'to fold the articleat a precise time regardless of the speed of advance of the conveyor rollers 38 and 40 and the conveyor V belts 9.

In accordance with one embodiment of the invention, two scanning elements, for example, photoelectric cells 13 and 14, are arranged at spaced locations to receive a light beam through aslot 44 from light'elernents 16 andj15, respectively. In this mannenthe photocell 13 controls maximum permissible forward location of the form 11 while the photoelectric cell 14 controls the maximum perrnissible rearward location ofthe form 1% which is being fed. At the foremost point therefore the beam coming from the light source 15 must always impinge on the photocell 13. At the rearrnost point the beam coming romthe light source 16 should always be covered by the form 10. V 7

An additional time control is effected by a photocell 17 which senses light from a light source 18 projected through an aperture or slot 19 of a disc 29 affixed to shaft '7 and rotatable therewith. The slot 19 is provided to align with the photocell 17 and the light source 13 when the folding operation is to take place. The photocell 17 is provided to control the photocells 13 and 14 and connects the cells only when the aperture 19 is located to indicateapproach ofknife blade 11 through a regulator 21. Regulator 21, in turn, controls the operation of the servo motor 4 in accordance with the sensed indications by the photocells 14- and 13. For example, if the article it covers up the photocell 13, then the folding knife 11 would normally push the article 16 into the roller later than desired. Therefore, the servo motor is actuated to 7 independent of the speed of operation of the machine.

It should be appreciated that control with only one photocell is possible but that the regulation would not be as steady as with the two photocell. control. Instead of V photocells, a scanning element may consist, at least in part, of electromagnetic pulse transmitters. As a means for the folding knife adjustment, 'while the machine is running, there are shown the two helical gears 2 and 3 but, of course, other means may also be provided. For

example, a planetary gear system with an adjustable outer ring or differential gear or a hydraulic arrangement for angularly shifting the knife l'lrnay be provided. Similar ly, a folding knife adjustment, when the machine is running, may be effected by hand instead of the servo motor- 4, and a hand wheel may advantageously be mounted on V conveyor tapes 9 which are trained to run around con- While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. A device for feeding articles including means for feeding a series of articles in succession along a path, folding knife means including a folding blade, means operable in synchronism with said feeding means for revolving said folding blade in one angular direction and at a substantially constant speed about'a first axis parallel to its length and to the path of movement of said articles while synchronously rotating said blade in the opposite angular direction about a second axis in spaced parallel relation to said'first axis for contacting each article as it is fed and folding it around said blade, means for phase shifting 'said folding blade during the operative movement thereof, and scanning means, adjacent said knife means and connected to said means for phase shifting said blade, effective to sense each article as it approaches said knife means and to phase shift said folding blade in either a lagging or a leading direction'in'accordance with the relative position of the sensed article along said path; said scanning means including first and second photocell means spaced along the path of feed' of said articles adjacent said knife means to sense the position of an article when it is in a position ready for folding, and control means connected to said first and second photocell means and effective to phase shift said folding blade in accordance with whether the article'is sensed by said first or said second photoelectric cell means.

2. A device for feeding articles including means for feedinga series of articles in succession along a path,

folding knife means including a folding blade, means operable in synchronism with said feeding means for revolving said folding blade. in one angular direction and at a substantially constant speed about a first axis parallel to its length and to the path of movement of said articles while synchronously rotating said blade in the opposite angular direction about a second axis in spaced parallel relation to said first axis for contacting each article as it is fed and folding it around said blade, means for phase shifting said folding blade during the operative'movement thereof, and scanning means, adjacent said knife means and connected to said means for phase shifting said blade, effective to sense each article 7 as it approaches said knife means and to phase shift said folding blade in either a lagging or a leading direction in accordance with the relative position of the sensed said first and second photocell means, when said article 'is scanned solely by said second photocell means, being shifting means to phase shift said folding blade in a leading direction.

the screw 5 for effecting this adjustment 7 llf a hand wheel 7 is provided, then the observation of the time for the shifting of the knife must be made by the operator.

References fitted by the Examiner V UNITED STATES PATENTS 2,583,580 1/52 Ludwig 101-181 'X 2,624,572 1/53 Harless 270-77 2,919,914 1/60 HarleSS 270-77 3,020,042 2/62 Worthington et al. 270-77 EUGENE R. cArozro, Primary Examiner. WILLIAM PENN, Examinen 

1. A DEVICE FOR FEEDING ARTICLES INCLUDING MEANS FOR FEEDING A SERIES OF ARTICLES IN SUCCESSION ALONG A PATH, FOLDING KNIFE MEANS INCLUDING A FOLDING BLADE, MEANS OPERABLE IN SYNCHRONISM WITH SAID FEEDING MEANS FOR REVOLVING SAID FOLDING BLADE IN ONE ANGULAR DIRECTION AND AT A SUBSTANTIALLY CONSTANT SPEED ABOUT A FIRST AXIS PARALLEL TO ITS LENGTH AND TO THE PATH OF MOVEMENT OF SAID ARTICLES WHILE SYNCHRONOUSLY ROTATING SAID BLADE IN THE OPPOSITE ANGULAR DIRECTION ABOUT A SECOND AXIS IN SPACED PARALLEL RELATION TO SAID FIRST AXIS FOR CONTACTING EACH ARTICLE AS IT IS FED AND FOLDING IT AROUND SAID BLADE, MEANS FOR PHASE SHIFTING SAID FOLDING BLADE DURING THE OPERATIVE MOVEMENT THEREOF, AND SCANNING MEANS, ADJACENT SAID KNIFE MEANS AND CONNECTED TO SAID MEANS FOR PHASE SHIFTING SAID BLADE, EFFECTIVE TO SENSE EACH ARTICLE AS IT APPROACHES SAID KNIFE MEANS AND TO PHASE SHIFT SAID FOLDING BLADE IN EITHER A LAGGING OR A LEADING DIRECTION IN ACCORDANCE WITH THE RELATIVE POSITION OF THE SENSED ARTICLE ALONG SAID PATH; SAID SCANNING MEANS INCLUDING FIRST AND SECOND PHOTOCELL MEANS SPACED ALONG THE PATH OF FEED OF SAID ARTICLES ADJACENT SAID KNIFE MEANS TO SENSE THE POSITION OF AN ARTICLE WHEN IT IS IN A POSITION READY FOR FOLDING, AND CONTROL MEANS CONNECTED TO SAID FIRST AND SECOND PHOTOCELL MEANS AND EFFECTIVE TO PHASE SHIFT SAID FOLDING BLADE IN ACCORDANCE WITH WHETHER THE ARTICLE IS SENSED BY SAID FIRST OR SAID SECOND PHOTOELECTRIC CELL MEANS. 